中国69个城市地下水挥发性卤代烃污染检测与特征研究

Investigation and research on volatile halogenated hydrocarbon contamination from groundwater in 69 cities of China

为了初步掌握中国主要城市地下水挥发性卤代烃污染状况和特征,在中国69个城市开展了地下水挥发性卤代烃污染检测与特征研究,采集地下水样品791组,采样井均为工农业生产和生活饮用水水井;依据US EPA 8260B检测方法,采用气相色谱/质谱联用分析仪器(P&T-GC/MS),分析和测试了氯仿、四氯化碳、1,1,1-三氯乙烷、三氯乙烯、四氯乙烯和二氯甲烷等15种挥发性卤代烃的质量浓度。结果表明:在791组地下水样品中,有406组样品至少有一种挥发性卤代烃组分被检出,检出率为51.33%;各组分中,氯仿的检出率最高,为20.35%,其他组分的检出率为0.25%～5.06%;氯乙烯在所有样品中均未检出;有13组样品的单项组分超标,超标率为1.64%;超标率由高到低分别为四氯化碳(0.76%)、氯仿(0.25%)、1,2-二氯乙烷(0.25%)、三氯乙烯(0.13%)、1,1,2-三氯乙烷(0.13%)、1,2-二氯丙烷(0.13%);超标井均为非供水水源地水井。检测与研究结果表明:中国主要城市地下水挥发性卤代烃污染物检出率较高,检测的69个城市中71%的城市至少有一种挥发性卤代烃被检出,且潜水的检出率高于承压水,但总体超标率较低。

In order to understand the contamination situation and characteristics of volatile halogenated hydrocarbon （VHH） in groundwater of main cities, China, the investigation and research on VHH contamination from groundwater in 69 cities of China were carried out. 791 groundwater samples were collected from wells for industrial and agricultural production and wells for living and drink; mass concentrations of 15 kinds of VHHs, which were chloroform, carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene, tetracarp, diehloromethane and so on, were analyzed with the analytical apparatus combined gas chromatography and mass spectrometry （P＆T-GC/MS） based on US EPA 8260B test method. The results showed that at least one kind of VHHs could be detected in 406 groundwater samples, and the detection ratio of the samples to the 791 groundwater samples was 51.33% ; the detection ratio for chloroform was highest （20. 35%） among the VHHs, and the ratios for other VHHs were 0. 25% -5.06%;no chloroethylene was detected in all the samples; mass concentrations of single VHH of 13 groundwater samples exceeded the standard value, and the over standard rate was 1.64%; VHHs with the over standard rate ranked in descending order were carbon tetrachloride （0.76%）, chloroform （0. 25 G ）, 1,2 dichloroethane （0. 25% ）, trichloroethylene （0. 13%）, 1,1,2 trichloroethane （0. 13%） and 1,2-dichloropropane （0.13%）; mass concentrations of VHHs from the wells in drinking water source area were lower than that in other areas. In general, the detection ratios of VHHs contamination from groundwater in main cities of China were high, at least one kind of VHHs could be detected in 71% of the 69 cities, and the detection ratios in unconfined aquifer were higher than that in confined aquifer, but the over standard rates were low.